Door opening and closing device for vehicles

ABSTRACT

A door opening and closing device for vehicles of the present invention includes: a motor drive mechanism; a first housing that accommodates the motor drive mechanism; a spindle drive mechanism connected to the motor drive mechanism; and a second housing that is arranged coaxially with the first housing and relatively moves with respect to the first housing by the spindle drive mechanism. The spindle drive mechanism includes: a spindle connected to the motor drive mechanism; a spindle nut screwed with the spindle; a push rod fixed so as not to rotate relative to the spindle nut and provided with a protrusion on its outer periphery; and a guide tube in which a guide groove guiding the protrusion of the push rod in an axial direction is formed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a national phase application in the United States ofInternational Patent Application No. PCT/JP2018/040313 with aninternational filing date of Oct. 30, 2018, which claims priorities ofJapanese Patent Applications No. 2017-214843 filed on Nov. 7, 2017, No.2017-214844 filed on Nov. 7, 2017, and No. 2018-184334 filed on Sep. 28,2018.

TECHNICAL FIELD

The present invention relates to a door opening and closing device forvehicles.

BACKGROUND ART

A drive device disclosed in JP 4430044 B includes a housing tube and acover tube that slidably guides the housing tube. The housing tubeincludes: a spindle drive having a threaded spindle and a spindle nutarranged on the threaded spindle; and a rotary drive that can drive thespindle drive in rotation. The threaded spindle is supported on thehousing tube so as to be rotatable and immovable in the axial direction,and is rotatably driven by the rotary drive. The spindle nut isnon-rotatably connected to the housing tube. In addition, the drivedevice also includes: a spindle tube concentrically surrounding thethreaded spindle; and a guide tube fixedly arranged to the housing tubeso as to surround the spindle tube with a clearance. One end of thespindle tube is connected to the spindle nut. In this drive device, whenthe threaded spindle is rotationally driven by the rotary drive, thecover tube moves in the axial direction together with the spindle nutand the spindle tube.

In addition, JP 4430044 B discloses a drive device including a rotationrestricting structure in which a spindle nut rotates along with rotationof a threaded spindle to prevent the spindle nut from rotating relativeto a guide tube. The rotation restricting structure includes: a wiperfixedly arranged to a spindle tube; and an axial slot provided so as topenetrate through the guide tube in a radial direction. As the wiperprotrudes through the axial slot, the spindle tube and the spindle nutconnected to the spindle tube, and the guide tube and the housing tubefixed to the guide tube are prevented from relatively rotating.

SUMMARY OT THE INVENTION Problems to be Solved by the Invention

However, in the driving device of JP 4430044 B, the spindle nut, thespindle tube fixedly arranged to the spindle nut, and a wiper arrangedfixedly to the spindle tube are formed as separate bodies, respectively.For this reason, the spindle nut rotates relative to the guide tube dueto a mounting situation of each part, variations of processingdimensions, or the like, so that there is a possibility that therotational driving of the threaded spindle is not efficiently convertedinto the linear movement of the spindle tube and spindle nut in theaxial direction.

An object of the present invention is to provide a door opening andclosing device for vehicles capable of effectively preventing relativerotation of a spindle nut with respect to a guide tube.

SUMMARY OF THE INVENTION

One aspect of the present invention provides a door opening and closingdevice for vehicles including: a motor drive mechanism; a first housingthat accommodates the motor drive mechanism; a spindle drive mechanismconnected to the motor drive mechanism; and a second housing that isarranged coaxially with the first housing and relatively moves withrespect to the first housing by the spindle drive mechanism. The spindledrive mechanism includes: a spindle connected to the motor drivemechanism; a spindle nut screwed with the spindle; a push rod fixed soas not to rotate relative to the spindle nut; a guide tube through whichthe push rod is inserted; and a relative rotation restricting portionthat restricts relative rotation between the push rod and the guidetube.

According to this door opening and closing device for vehicles, therelative rotation between the push rod and the guide tube is restrictedby the relative rotation restricting portion so that the rotationalmovement of the spindle is converted into relative movement of thespindle nut and the push rod with respect to the guide tube, and therelative rotation of the spindle nut with respect to the guide tube canbe effectively prevented.

One aspect of the present invention provides a door opening and closingdevice for vehicles including: a motor drive mechanism; a first housingthat accommodates the motor drive mechanism; a spindle drive mechanismconnected to the motor drive mechanism; and a second housing that isarranged coaxially with the first housing and relatively moves withrespect to the first housing by the spindle drive mechanism. The spindledrive mechanism includes: a spindle connected to the motor drivemechanism; a spindle nut screwed with the spindle; a push rod fixed soas not to rotate relative to the spindle nut and provided with aprotrusion on its outer periphery; and a guide tube in which a guidegroove guiding the protrusion of the push rod in an axial direction isformed.

According to this door opening and closing device for vehicles, the pushrod is fixed so as not to rotate relative to the spindle nut, and theprotrusion of the push rod is guided through the guide groove of theguide tube in the axial direction. For this reason, the rotationalmovement of the spindle is converted into the relative movement of thespindle nut and the push rod with respect to the guide tube, and therelative rotation of the spindle nut with respect to the guide tube canbe effectively prevented.

One aspect of the present invention provides a door opening and closingdevice for vehicles including: a motor drive mechanism; a first housingthat accommodates the motor drive mechanism; a spindle drive mechanismconnected to the motor drive mechanism; and a second housing that isarranged coaxially with the first housing and relatively moves withrespect to the first housing by the spindle drive mechanism. The spindledrive mechanism includes: a spindle connected to the motor drivemechanism; a spindle nut screwed with the spindle; a push rod fixed soas not to rotate relative to the spindle nut and having an outerperipheral surface whose cross section orthogonal to a longitudinaldirection forms a polygon; and a guide tube having a guide portionthrough which the push rod is inserted. The guide portion has an innerperipheral surface whose cross section orthogonal to the longitudinaldirection of the guide tube forms a shape corresponding to the outerperipheral surface of the push rod.

According to this door opening and closing device for vehicles, thespindle nut is fixed to the push rod so as not to rotate relative to thepush rod. In addition, since the push rod is inserted through the guideportion of the guide tube, the rotational movement of the spindle isconverted into the relative movement of the spindle nut and the push rodwith respect to the guide tube. For this reason, the relative rotationof the spindle nut with respect to the guide tube can be prevented.

The door opening and closing device for vehicles of the presentinvention can prevent the relative rotation of the spindle nut withrespect to the guide tube.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a rear portion of a body forvehicles in which a door opening and closing device for vehiclesaccording to a first embodiment of the present invention is employed;

FIG. 2 is a longitudinal cross-sectional view of the door opening andclosing device for vehicles according to the first embodiment;

FIG. 3 is an exploded perspective view of a push rod and a spindle nut;

FIG. 4 is an exploded perspective view of a guide tube and the push rodintegrally provided with the spindle nut;

FIG. 5 is a longitudinal cross-sectional view of the door opening andclosing device for vehicles in a stretched state;

FIG. 6 is a perspective view of a push rod of a door opening and closingdevice for vehicles according to a second embodiment of the presentinvention;

FIG. 7 is a schematic longitudinal cross-sectional view of a cylindricalmember used for manufacturing the push rod according to the secondembodiment;

FIG. 8 is a longitudinal cross-sectional view similar to FIG. 7 of thepush rod obtained by pressing the cylindrical member;

FIG. 9 is an exploded perspective view of a push rod and a spindle nutof a door opening and closing device for vehicles according to a thirdembodiment of the present invention;

FIG. 10 is a perspective view of the push rod integrally provided withthe spindle nut according to the third embodiment;

FIG. 11 is a front view of a cylindrical member used for manufacturingthe push rod according to the third embodiment;

FIG. 12 is an exploded perspective view of a push rod and a spindle nutof a door opening and closing device for vehicles according to a fourthembodiment of the present invention;

FIG. 13 is an exploded perspective view of a guide tube and the push rodintegrally provided with the spindle nut according to a fourthembodiment;

FIG. 14 is a perspective view of a cover, a push rod integrally providedwith a spindle nut, and a spindle of a door opening and closing devicefor vehicles according to a fifth embodiment of the present invention;

FIG. 15 is a cross-sectional view taken along line XV-XV in FIG. 14;

FIG. 16 is a perspective view of a cover, a push rod integrally providedwith a spindle nut, and a spindle of a door opening and closing devicefor vehicles according to a sixth embodiment of the present invention;

FIG. 17 is a cross-sectional view taken along line XVII-XVII in FIG. 16;

FIG. 18 is a perspective view of a guide tube and a push rod integrallyprovided with a spindle nut of a door opening and closing device forvehicles according to a seventh embodiment of the present invention;

FIG. 19 is a perspective view of the push rod according to the seventhembodiment;

FIG. 20 is a perspective view of the guide tube and the push rodintegrally provided with the spindle nut according to the seventhembodiment;

FIG. 21 is a cross-sectional view taken along line XXI-XXI in FIG. 18;

FIG. 22 is a perspective view illustrating a rear portion of a vehiclebody in which a door opening and closing device for vehicles accordingto an eighth embodiment of the present invention is employed;

FIG. 23 is a longitudinal cross-sectional view of the door opening andclosing device for vehicles according to the eighth embodiment of thepresent invention;

FIG. 24 is an exploded perspective view of a push rod and a spindle nut;

FIG. 25 is an exploded perspective view of a guide tube and the push rodintegrally provided with the spindle nut;

FIG. 26 is a perspective view of the guide tube and the push rod asviewed from the rear side;

FIG. 27 is a rear view of the guide tube, the push rod, and the spindlenut; and

FIG. 28 is a longitudinal cross-sectional view of the door opening andclosing device for vehicles in a stretched state.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiments of the present invention will be described withreference to the accompanying drawings.

First Embodiment

Referring to FIG. 1, a door opening and closing device 1 for vehiclesaccording to a first embodiment of the present invention has acylindrical shape and is connected to a door 2 a and a body 2 b of avehicle 2. When the door opening and closing device for vehicles 1stretches and contracts, the door 2 a is driven to be open and closed.In the following description, “axial direction”, “circumferentialdirection”, and “radial direction” indicate the axial direction, thecircumferential direction, and the radial direction of the door openingand closing device 1 for vehicles, respectively.

Referring to FIG. 2, the door opening and closing device 1 for vehiclesaccording to the first embodiment includes a first housing 10, a secondhousing 20, a motor drive mechanism 30, and a spindle drive mechanism40.

The first housing 10 includes a cylindrical accommodating portion 11that accommodates the motor drive mechanism 30, and a cylindrical cover12 that is screwed and fixed to the accommodating portion 11. Here, thefirst housing 10 may have a structure in which the accommodating portion11 and the cover 12 are integrated. One end (right end in the drawing)of the accommodating portion 11 in the axial direction is open, and isclosed by a shaft end member 13. The first housing 10 is connected tothe body 2 b of the vehicle 2 via a ball joint (not illustrated)connected to the shaft end member 13.

The second housing 20 is cylindrical, and an outer diameter of thesecond housing 20 is smaller than an inner diameter of the first housing10. The second housing 20 is arranged coaxially with the first housing10, and is accommodated inside the first housing 10 so as to be movablerelative to the first housing 10 in the axial direction. One end of thesecond housing 20 is closed by a shaft end member 21. The second housing20 is connected to the door 2 a of the vehicle 2 via a ball joint (notillustrated) connected to the shaft end member 21. In addition, a coilspring 22 is arranged coaxially with the second housing 20 inside thesecond housing 20 in the radial direction.

One end (right end in the drawing) of the coil spring 22 abuts on thefirst housing 10, and the other end (left end in the drawing) of thecoil spring 22 abuts on the second housing 20. The coil spring 22 isarranged in a compressed state, and elastically biases the first housing10 and the second housing 20 in a direction in which the door openingand closing device 1 for vehicles stretches.

The motor drive mechanism 30 includes an electric motor 31 that is adrive source, and a decelerator 32 that reduces the rotational speed ofthe electric motor 31. The motor drive mechanism 30 is accommodatedinside the accommodating portion 11 of the first housing 10.

The spindle drive mechanism 40 includes a spindle 50, a spindle nut 60,a push rod 70, and a guide tube 80. The spindle drive mechanism 40 isarranged inside the coil spring 22 in the radial direction.Specifically, in the radial direction, the guide tube 80 is arrangedinside the coil spring 22, and the push rod 70 is accommodated insidethe guide tube 80. In addition, the spindle nut 60 is fixed to one endof the push rod 70. The spindle 50 is arranged inside the push rod 70and the spindle nut 60 in the radial direction.

As illustrated most clearly in FIG. 2, the spindle 50 is provided with athread groove 50 a on its outer peripheral surface. The spindle 50 iscoaxially arranged in the first housing 10. As illustrated most clearlyin FIG. 2, a proximal end 50 b of the spindle 50 is rotatably supportedby a bearing 14 provided in the first housing 10. In addition, thespindle 50 is mechanically connected to a rotating shaft of the electricmotor 31 via the decelerator 32, and is rotationally driven by theelectric motor 31.

A thread groove 60 a is provided on an inner peripheral surface of thespindle nut 60, and is screwed with the thread groove 50 a of thespindle 50. Referring also to FIG. 3, the spindle nut 60 includes convexportions 61 and engagement protrusions 62 on its outer periphery. Theconvex portion 61 of the present embodiment has a substantiallyrectangular cross section in a cross section orthogonal to the axialdirection. In addition, the convex portion 61 of the spindle nut 60 ofthe present embodiment is provided at three equally spaced locations inthe circumferential direction of the spindle nut 60, and the engagementprotrusions 62 are provided four by four between the adjacent convexportions 61 in the circumferential direction. Here, the spindle nut 60of the present embodiment is made of resin.

Referring to FIGS. 2 and 3, the push rod 70 is cylindrical, and an endon a side opposite to the spindle nut 60 side is fixed to one end (onthe shaft end member 21 side) of the second housing 20. An innerdiameter of the push rod 70 is substantially the same as an outerdiameter of the spindle nut 60. The push rod 70 has a protrusion 71 onits outer periphery and an engagement hole 72 with which the engagementprotrusion 62 of the spindle nut 60 is engaged. The protrusion 71 has aconcave portion 71 a in which the convex portion 61 of the spindle nut60 is fitted on its inner periphery, and a wall 71 b erected uprightfrom the push rod 70 in the axial direction. The push rod 70 and thespindle nut 60 are coaxially fixed by fitting the concave portion 71 aof the protrusion 71 and the convex portion 61 of the spindle nut 60.

The push rod 70 of the present embodiment is made of metal, and theprotrusion 71 is molded by press working. In the present embodiment, thespindle nut 60 made of resin and the push rod 70 made of metal areintegrally molded by insert-molding. In addition, as illustrated mostclearly in FIG. 2, a resin rotor 73 that rotatably supports the distalend 50 c of the spindle 50 on the inner periphery of the push rod 70without rattling is provided on the inner periphery of the push rod 70.The spindle 50 having both ends supported by the bearing 14 provided inthe first housing 10 and the resin rotor 73 provided on the distal end50 c of the spindle 50, and is arranged coaxially with the first housing10.

The guide tube 80 is cylindrical and is fixed to the first housing 10.An inner diameter of the guide tube 80 is larger than an outer diameterof the push rod 70. A guide groove 81 that accommodates the protrusion71 of the push rod 70 and guides the protrusion 71 in the axialdirection is formed on the inner periphery of the guide tube 80. Asillustrated in FIG. 4, when the guide groove 81 of the guide tube 80 andthe protrusion 71 of the push rod 70 are engaged, the push rod 70 isattached to the guide tube 80 so as to be relatively movable and not tobe relatively rotatable. In addition, as illustrated most clearly inFIG. 2, the guide tube 80 is provided with a locking portion 82, whichcan lock the protrusion 71 of the push rod 70, at an end of the guidegroove 81. The locking portion 82 has a locking surface 82 a thatopposes the wall 71 b of the protrusion 71 and is perpendicular to theaxial direction.

In a state where the door 2 a of the vehicle 2 is closed, the coilspring 22 is in the most compressed state in the door opening andclosing device 1 for vehicles, and the spindle nut 60 is located nearthe proximal end 50 b of the spindle 50 as illustrated in FIG. 2. Whenthe electric motor 31 is driven from this state, the rotation of anoutput shaft of the electric motor 31 is reduced by the decelerator 32and transmitted to the spindle 50, and the spindle 50 is rotationallydriven. Since the spindle nut 60 and the push rod 70 are engaged withthe guide tube 80 and the first housing 10 so as not to relativelyrotate, the rotational movement of the spindle 50 is converted into thelinear movement of the spindle nut 60 with respect to the guide tube 80.Specifically, the spindle nut 60 and the push rod 70 move in the axialdirection along the guide groove 81 of the guide tube 80. Along with themovement of the push rod 70, the second housing 20 moves relative to thefirst housing 10. Since the first housing 10 and the second housing 20relatively move as described above, the door opening and closing device1 for vehicles stretches and drives the door 2 a connected via the shaftend member 21 up to an open position. Here, as illustrated most clearlyin FIG. 5, the relative movement of the push rod 70 with respect to theguide tube 80 is restricted as the wall 71 b of the protrusion 71 andthe locking surface 82 a of the locking portion 82 abuts on each other.

As the convex portion 61 of the spindle nut 60 is fitted into theconcave portion 71 a provided on the protrusion 71 of the push rod 70,the push rod 70 and the spindle nut 60 are fixed. In addition, as theprotrusion 71 of the push rod 70 is accommodated in the guide groove 81of the guide tube 80, the rotational movement of the spindle 50 isconverted into the relative movement of the spindle nut 60 and the pushrod 70 with respect to the guide tube 80. For this reason, the relativerotation of the spindle nut 60 with respect to the guide tube 80 can beprevented.

The protrusion 71 provided on the outer periphery of the push rod 70 andthe guide groove 81, which is formed in the guide tube 80 and guides theprotrusion 71 of the push rod 70 in the axial direction, constitute arelative rotation restricting portion.

Since the spindle nut 60 is molded integrally with the push rod 70 byinsert-molding, it is possible to prevent the spindle nut 60 fromrotating relative to the push rod 70 and from falling off.

Since the push rod 70 and the spindle nut 60 are fixed by the engagementbetween the engagement protrusion 62 and the engagement hole 72, thespindle nut 60 can be prevented from falling off from the push rod 70.

As the protrusion 71 of the push rod 70 is locked in the axial directionby the locking portion 82 provided in the guide groove 81 of the guidetube 80, the relative movement between the guide tube 80 and the pushrod 70 is restricted. That is, since the protrusion 71 of the push rod70 can restrict the relative movement and the relative rotation of thepush rod 70 with respect to the guide tube 80, it is unnecessary to usea separate component for restricting the relative movement between theguide tube 80 and the push rod 70.

The spindle nut 60 rotationally driven by the spindle 50, the push rod70 moving with the spindle nut 60, and the protrusion 71 that preventsthe relative rotation of the push rod 70 with respect to the guide tube80 operate integrally. The rotational movement of the spindle 50 isdirectly converted into the relative movement of the spindle nut 60 withrespect to the guide tube 80 by the protrusion 71 that operatesintegrally with the spindle nut 60. For this reason, the relativerotation of the spindle nut 60 with respect to the guide tube 80 can beeffectively prevented.

Note that the spindle nut 60 is fixed to the inner circumferential sideof one end of the push rod 70 where the protrusion 71 is provided in thefirst embodiment, but the spindle nut may be arranged on the innerperiphery of the push rod 70 with an interval from the protrusion 71.

Second Embodiment

A door opening and closing device for vehicles according to a secondembodiment of the present invention has the same configuration as thatof the door opening and closing device 1 for vehicles of the firstembodiment except for a slit S of the push rod 70.

Referring to FIG. 6, the push rod 70 in the door opening and closingdevice for vehicles according to the second embodiment includes the slitS which is adjacent to the protrusion 71 in the axial direction andextends in the circumferential direction.

The protrusion 71 of the second embodiment is formed by press working.Specifically, the push rod 70 having the protrusion 71 is manufacturedusing a cylindrical member 90 made of metal as illustrated in FIG. 7.The cylindrical member 90 includes a first portion 90 a which issubjected to the press working and a second portion 90 b which is notsubjected to the press working. The slit S extending in thecircumferential direction is provided between the first portion 90 a andthe second portion 90 b. The protrusion 71 of the push rod 70 is formedby pressing the first portion 90 a of the cylindrical member 90 from theinside (see a broken arrow in FIG. 7). As illustrated in FIG. 8, thewall 71 b is formed to be erected upright in the axial direction.

In the case of not providing the slit S, the first portion 90 ais/mechanically restrained by the second portion 90 b when the firstportion 90 a is pressed, and thus, it is difficult to form the wall 71 bof the protrusion 71 so as to be erected upright in the axial directionin some cases (see a two-dot chain line in FIG. 8). Since the slit S isprovided, the first portion 90 a and the second portion 90 b aredivided, and the first portion 90 a is not mechanically restrained bythe second portion 90 b, and thus, the wall 71 b can be formed asintended. For this reason, the relative position for restricting therelative movement of the push rod 70 with respect to the guide tube 80can be accurately determined.

Third Embodiment

A door opening and closing device for vehicles according to a thirdembodiment of the present invention has the same configuration as thatof the door opening and closing device 1 for vehicles of the firstembodiment except for a push rod 170.

Referring to FIG. 9, each of protrusions 171 of the push rod 170 in thedoor opening and closing device for vehicles according to the thirdembodiment has a pair of side walls 172 which are erected upright in theaxial direction from the push rod 170 and extend in the axial direction.The pair of side walls 172 are spaced apart in the circumferentialdirection of the push rod 170. In addition, the push rod 170 of thethird embodiment includes the slit S which is adjacent to the protrusion171 in the axial direction and extends in the circumferential direction,which is similar to the second embodiment.

Referring to FIG. 10, the spindle nut 60 and the push rod 170 areintegrally molded by insert-molding. The convex portion 61 of thespindle nut 60 is formed between the pair of side walls 172, and theouter peripheral surface 61 a of the convex portion 61 of the spindlenut 60 is formed so as to be smoothly continuous to outer peripheralsurfaces 172 a of the pair of side walls 172.

The push rod 170 of the present embodiment is manufactured using, forexample, a cylindrical member 190 made of metal as illustrated in FIG.11. The cylindrical member 190 is provided with a cut 191, which dividesthe cylindrical member 190 in the circumferential direction and extendsin the axial direction, and the side wall 172 is formed by bending aportion divided by the cut 191 from the radially inner side to theoutside (see an arrow in the drawing).

In the present embodiment, the side walls 172 of the push rod 170 isdivided in the circumferential direction and are not mechanicallyrestrained from each other, and thus, it is possible to easily form theprotrusion 171 as intended by forming the side walls 172 by bending. Inaddition, since the slit S is provided to be adjacent to the protrusion171 in the axial direction, the side wall 172 is not mechanicallyrestrained in the axial direction, and the protrusion 171 can be formedwithout twisting an axial end of the side wall 172.

Fourth Embodiment

A door opening and closing device for vehicles according to a fourthembodiment of the present invention has the same configuration as thatof the door opening and closing device 1 for vehicles of the firstembodiment except for a push rod 270 and a guide tube 280.

Referring to FIGS. 12 and 13, the push rod 270 in the door opening andclosing device for vehicles according to the fourth embodiment has asubstantially cylindrical shape, and has an outer peripheral surface 270a that forms a circle in a cross section orthogonal to a longitudinaldirection of the push rod 270. In addition, the push rod 270 has anouter peripheral surface, which forms a hexagon in a cross sectionorthogonal to the longitudinal direction of the push rod 270, at oneend. Specifically, at one end, the push rod 270 includes six outerperipheral surfaces 270 b, each of which is a flat surface, and sixprotrusions 271 are formed by two outer peripheral surfaces 270 b thatare adjacent to each other in the circumferential direction. Theprotrusion 271 forms a wall 271 a extending perpendicularly to the axialdirection of the push rod 270 from the outer peripheral surface 270 a ofthe push rod 270. A plurality of (four in the illustrated embodiment)through-holes 272 are formed in each of the outer peripheral surfaces270 b of the push rod 270.

Referring to FIG. 13, an inner peripheral surface of the guide tube 280has a shape corresponding to the outer peripheral surface 270 b of thepush rod 270 such that the push rod 270 can slide. The inner peripheralsurface of the guide tube 280 of the present embodiment forms a hexagonin a cross section orthogonal to a longitudinal direction of the guidetube 280. Specifically, the guide tube 280 includes six inner peripheralsurfaces 280 a each of which is a flat surface and opposes the outerperipheral surface 270 b of the push rod 270. That is, in the crosssection orthogonal to the axial direction, the cross-sectional shapeformed by the inner peripheral surface 280 a of the guide tube 280 is ashape that is similar to and slightly larger than the cross-sectionalshape of the outer peripheral surface 270 b of the push rod 270. A guidegroove 281, which accommodates the protrusion 271 and guiding theprotrusion 271 in the axial direction, is formed in an inner peripheryof the guide tube 280 by the two inner peripheral surfaces 280 aadjacent in the circumferential direction. Note that the guide tube 280is provided with a locking portion 282 that can lock the protrusion 271of the push rod 270 at an end of the guide groove 281. The lockingportion 282 is formed to have a cylindrical cross section with a lockingsurface 282 a, which opposes the wall 271 a of the protrusion 271 and isperpendicular to the axial direction, and holds an outer peripheralsurface of the outer peripheral surface 270 a of the push rod 270 in theradial direction.

In the fourth embodiment, the same operations and effects as those ofthe first embodiment are achieved.

Fifth Embodiment

A door opening and closing device for vehicles according to a fifthembodiment of the present invention has the same configuration as thatof the door opening and closing device 1 for vehicles of the firstembodiment except for a spindle drive mechanism and a cover 312.

Referring to FIGS. 14 and 15, the spindle drive mechanism in the dooropening and closing device for vehicles according to the fifthembodiment includes a spindle 350, a spindle nut 360, a push rod 370,and a guide tube 380. Note that FIG. 15 is a cross-sectional view takenalong line XV-XV in FIG. 14.

The push rod 370 includes four protrusions 371 provided on its outerperiphery, and an engagement hole 372 with which an engagementprotrusion 362 of the spindle nut 360 is engaged. The four protrusions371 are provided on the outer periphery of the push rod 370 at equalintervals in the circumferential direction. In addition, the protrusion371 has, on its inner periphery, a concave portion 371 a in which aconvex portion 361 of the spindle nut 360 is fitted. The push rod 370and the spindle nut 360 are coaxially fixed by fitting the concaveportion 371 a of the protrusion 371 and the convex portion 361 of thespindle nut 360. The push rod 370 is made of metal, and the protrusion371 is molded by press working. In the present embodiment, the spindlenut 360 made of resin and the push rod 370 made of metal are integrallymolded by insert-molding.

The guide tube 380 is cylindrical and is provided on an inner peripheryof the cover 312. A guide groove 381 that guides the protrusion 371 ofthe push rod 370 in the axial direction is formed on an inner peripheryof the guide tube 380. As the guide groove 381 of the guide tube 380 isengaged with the protrusion 371 of the push rod 370, the push rod 370 isattached to the guide tube 380 so as to be relatively movable in theaxial direction, and the relative rotation with respect to the guidetube 380 is restricted. In addition, the guide tube 380 is provided witha locking portion (not illustrated), which can lock the protrusion 371of the push rod 370, at an end of the guide groove 381.

Note that the second housing 20 and the coil spring 22 arranged betweenthe cover 312 and the guide tube 380 are omitted in FIG. 15.

In the fifth embodiment, the same operations and effects as those of thefirst embodiment are achieved.

Sixth Embodiment

A door opening and closing device for vehicles according to a sixthembodiment of the present invention has the same configuration as thatof the door opening and closing device for vehicles of the fifthembodiment except for a spindle nut 460 and a push rod 470.

Referring to FIGS. 16 and 17, the spindle drive mechanism in the dooropening and closing device for vehicles according to the sixthembodiment includes the spindle 350, a spindle nut 460, a push rod 470,and the guide tube 380. Note that FIG. 17 is a cross-sectional viewtaken along line XVII-XVII in FIG. 16.

The push rod 470 includes four protrusions 471 provided on its outerperiphery, and a plurality of engagement holes 472 provided on the otherend side of the protrusion 471 in the axial direction. The fourprotrusions 471 are provided on the outer periphery of the push rod 470at equal intervals in the circumferential direction. An engagementprotrusion 462 of the spindle nut 460 is engaged with the engagementhole 472 of the push rod 470. In the present embodiment in which thepush rod 470 is made of metal and the protrusion 471 is molded by pressworking, the spindle nut 360 made of resin and the push rod 470 made ofmetal are integrally molded by insert-molding.

The guide tube 380 is cylindrical and is provided on an inner peripheryof the cover 312. The cover 312 and the guide tube 380 are integrallyformed. The guide groove 381 that guides the protrusion 471 of the pushrod 470 in the axial direction is formed on an inner periphery of theguide tube 380. As the guide groove 381 of the guide tube 380 is engagedwith the protrusion 471 of the push rod 470, the push rod 470 isattached to the guide tube 380 so as to be relatively movable in theaxial direction, and the relative rotation with respect to the guidetube 380 is restricted. In addition, the guide tube 380 is provided witha locking portion (not illustrated), which can lock the protrusion 471of the push rod 470, at an end of the guide groove 381.

Note that the second housing 20 and the coil spring 22 arranged betweenthe cover 312 and the guide tube 380 are omitted in FIG. 17.

In this manner, in the door opening and closing device for vehiclesaccording to the sixth embodiment, the spindle nut 460 is arranged noton the inner periphery one of a first end side of the push rod 470 wherethe protrusion 471 is provided but on the inner periphery of the pushrod 470 so as to be closer to a second end of the push rod 470 than isthe protrusion 471.

The spindle nut 460 is arranged on the inner periphery of the push rod470 with an interval from the protrusion 471.

In the sixth embodiment, the same operations and effects as those of thefirst embodiment are achieved.

Seventh Embodiment

A door opening and closing device for vehicles according to a seventhembodiment of the present invention has the same configuration as thatof the door opening and closing device 1 for vehicles of the firstembodiment except for a spindle drive mechanism.

Referring to FIGS. 18 to 20, the spindle drive mechanism in the dooropening and closing device for vehicles according to the seventhembodiment includes: the spindle 50 (illustrated in FIG. 2), a spindlenut 560, a push rod 570, and a guide tube 580. The guide tube 580 iscylindrical and is provided on an inner periphery of the cover 12(illustrated in FIG. 1).

The push rod 570 includes a pair of protrusions 571 provided on itsouter periphery, and a hole 572 (illustrated in FIG. 19) configured toconnect the spindle nut 560, a semi-cylindrical portion 561, and asemi-cylindrical portion 562. The pair of protrusions 571 are providedat positions radially opposing an outer periphery of the push rod 570over the entire length of the push rod 570 in the axial direction. Asthe spindle nut 560, the semi-cylindrical portion 561, and thesemi-cylindrical portion 562 are connected via the hole 572, the pushrod 570 and the spindle nut 560 are coaxially fixed. In the presentembodiment, the spindle nut 560, the semi-cylindrical portion 561, thesemi-cylindrical portion 562, which are made of resin, and the push rod570 made of metal are integrally molded by insert-molding.

Referring to FIGS. 20 and 21, a locking portion 582 is provided in anannular shape on an inner periphery on a distal end side of the guidetube 580. A pair of guide grooves 581, which guide the protrusion 571 ofthe push rod 570 in the axial direction, are formed at positionsradially opposing the locking portion 582. Note that FIG. 21 is across-sectional view taken along line XXI-XXI in FIG. 18.

As the guide groove 581 of the guide tube 580 is engaged with theprotrusion 571 of the push rod 570, the push rod 570 is attached to theguide tube 580 so as to be relatively movable in the axial direction,and the relative rotation with respect to the guide tube 580 isrestricted. In addition, as a wall surface 561 a of the semi-cylindricalportion 561 and a wall surface 562 a of the semi-cylindrical portion 562on the push rod 370 side abut on a locking surface 582 a of the lockingportion 582 of the guide tube 580, the movement of the push rod 370 inthe axial direction is restricted.

In the seventh embodiment, the protrusions 571 provided over the entirelength of the push rod 570 in the axial direction at the positionsradially opposing the outer periphery of the push rod 570 are engagedwith the guide grooves 581 provided in the locking portion 582 of theguide tube 580, so that the push rod 570 is attached to the guide tube380 so as to be relatively movable in the axial direction, and therelative rotation with respect to the guide tube 580 is restricted.

Note that the pair of protrusions 571 are provided on the outerperiphery of the push rod 570 in the seventh embodiment, but one orthree or more protrusions may be provided on the outer periphery of thepush rod at intervals in the circumferential direction.

The door opening and closing device for vehicles of the presentinvention is not limited to the configurations of the first to seventhembodiments, and various modifications can be made.

For example, in the first embodiment, the push rod 70 may include anengagement protrusion, and the spindle nut 60 may include an engagementhole within a range that does not affect the thread groove 60 a.

In addition, the first housing 10 is not necessarily divided into theaccommodating portion 11 and the cover 12.

Eighth Embodiment

Referring to FIG. 22, a door opening and closing device 1 for vehicles1001 according to an eighth embodiment of the present invention has acylindrical shape, and is connected to a door 1002 a and a body 1002 bof a vehicle 1002. When the door opening and closing device 1 forvehicles 1001 stretches and contracts, the door 1002 a is driven to beopen and closed. In the following description, “axial direction”,“circumferential direction”, and “radial direction” indicate the axialdirection, the circumferential direction, and the radial direction ofthe door opening and closing device 1 for vehicles 1001, respectively.

Referring to FIG. 23, the door opening and closing device 1 for vehicles1001 according to the present embodiment includes a first housing 1010,a second housing 1020, a motor drive mechanism 1030, and a spindle drivemechanism 1040.

The first housing 1010 includes a cylindrical accommodating portion 1011that accommodates the motor drive mechanism 1030, and a cylindricalcover 1012 that is screwed and fixed to the accommodating portion 1011.Here, the first housing 1010 may have a structure in which theaccommodating portion 1011 and the cover 1012 are integrated. One end(right end in the drawing) of the accommodating portion 1011 in theaxial direction is open, and is closed by a shaft end member 1013. Thefirst housing 1010 is connected to the body 1002 b of the vehicle 1002via a ball joint (not illustrated) connected to the shaft end member1013.

The second housing 1020 is cylindrical, and an outer diameter of thesecond housing 1020 is smaller than an inner diameter of the firsthousing 1010. The second housing 1020 is arranged coaxially with thefirst housing 1010, and is accommodated inside the first housing 1010 soas to be movable relative to the first housing 1010 in the axialdirection. One end of the second housing 1020 is closed by a shaft endmember 1021. The second housing 1020 is connected to the door 1002 a ofthe vehicle 1002 via a ball joint (not illustrated) connected to theshaft end member 1021. In addition, a coil spring 1022 is arrangedcoaxially with the second housing 1020 inside the second housing 1020 inthe radial direction.

One end (right end in the drawing) of the coil spring 1022 abuts on thefirst housing 1010, and the other end (left end in the drawing) of thecoil spring 1022 abuts on the second housing 1020. The coil spring 1022is arranged in a compressed state, and elastically biases the firsthousing 1010 and the second housing 1020 in a direction in which thedoor opening and closing device 1 for vehicles 1001 stretches.

The motor drive mechanism 1030 includes an electric motor 1031 that is adrive source, and a decelerator 1032 that reduces the rotational speedof the electric motor 1031. The motor drive mechanism 1030 isaccommodated inside the accommodating portion 1011 of the first housing1010.

The spindle drive mechanism 1040 includes a spindle 1050, a spindle nut1060, a push rod 1070, and a guide tube 1080. The spindle drivemechanism 1040 is arranged inside the coil spring 1022 in the radialdirection. Specifically, in the radial direction, the guide tube 1080 isarranged inside the coil spring 1022, and the push rod 1070 isaccommodated inside the guide tube 1080. In addition, the spindle nut1060 is fixed to one end of the push rod 1070. The spindle 1050 isarranged inside the push rod 1070 and the spindle nut 1060 in the radialdirection.

As illustrated most clearly in FIG. 23, the spindle 1050 is providedwith a thread groove 1050 a on its outer peripheral surface. The spindle1050 is coaxially arranged in the first housing 1010. As illustratedmost clearly in FIG. 23, a proximal end 1050 b of the spindle 1050 isrotatably supported by a bearing 1014 provided in the first housing1010. In addition, the spindle 1050 is mechanically connected to arotating shaft of the electric motor 1031 via the decelerator 1032, andis rotationally driven by the electric motor 1031.

Referring to FIG. 24, the spindle nut 1060 is cylindrical, and has alarger diameter than that of an outer peripheral surface 1070 a of thepush rod 1070 having a substantially rectangular cylindrical shape whichwill be described later. Referring also to FIG. 23, a thread groove 1060a is formed on an inner peripheral surface of the spindle nut 1060, andis screwed with the thread groove 1050 a provided on the outer peripheryof the spindle 1050. The spindle nut 1060 of the present embodiment ismade of resin.

The push rod 1070 is substantially rectangular cylindrical, and has ahexagonal outer peripheral surface and a circular inner peripheralsurface in a cross section orthogonal to a longitudinal direction of thepush rod 1070. Specifically, the push rod 1070 has six outer peripheralsurfaces 1070 a each of which is a flat surface. A plurality of (five inthe illustrated embodiment) through-holes 1071 are formed in each of theouter peripheral surfaces 1070 a of the push rod 1070 of the presentembodiment. The push rod 1070 is fixed at one end in the axial directionso as not to rotate relative to the spindle nut 1060. In the presentembodiment, the spindle nut 1060 made of resin and the push rod 1070made of metal are integrally molded by insert-molding. As describedabove, the spindle nut 1060 has the larger diameter than that of theouter peripheral surface 1070 a of the push rod 1070, and forms a wall1060 b extending perpendicularly to the axial direction of the push rod1070 from the outer peripheral surface 1070 a of the push rod 1070 inthe state fixed to the push rod 1070 as illustrated most clearly in FIG.23. In addition, as illustrated most clearly in FIG. 23, a resinmaterial of the spindle nut 1060 filling the inside of the through-hole1071 of the push rod 1070 forms a columnar engagement portion 1061 ofthe spindle nut 1060 that engages with the through-hole 1071. A resinrotor 1072 that rotatably supports a distal end 1050 c of the spindle1050 on the inner periphery of the push rod 1070 without rattling isprovided on the inner periphery of the push rod 1070. The spindle 1050having both ends supported by the bearing 1014 provided in the firsthousing 1010 and the resin rotor 1072 provided on the distal end 1050 cof the spindle 1050, and is arranged coaxially with the first housing1010.

Referring to FIG. 23, the guide tube 1080 is fixed to the first housing1010. Referring FIGS. 25 and 26 together, the guide tube 1080 includes acylindrical main body 1081 and a guide portion 1082 which is provided atone end of the main body 1081 and through which the push rod 1070 isinserted. An inner peripheral surface of the main body 1081 of the guidetube 1080 is circular in a cross section orthogonal to the axialdirection. The push rod 1070 is accommodated in the main body 1081 ofthe guide tube 1080, and the inner peripheral surface of the main body1081 of the guide tube 1080 opposes the outer peripheral surface 1070 aof the push rod with a sufficient interval. Referring to FIG. 27, aninner peripheral surface of the guide portion 1082 has a shapecorresponding to the outer peripheral surface 1070 a of the push rod1070 such that the push rod 1070 can slide. In the present embodiment,the inner peripheral surface of the guide portion 1082 is hexagonal in across section orthogonal to the longitudinal direction of the guide tube1080. Specifically, the guide portion 1082 has six inner peripheralsurfaces 1082 a each of which is a flat surface and opposes the outerperipheral surface 1070 a of the push rod 1070. That is, in the crosssection orthogonal to the axial direction, the cross-sectional shape ofthe inner peripheral surface 1082 a of the guide portion 1082 is a shapethat is similar to and slightly smaller than the cross-sectional shapeof the outer peripheral surface 1070 a of the push rod 1070. The pushrod 1070 is attached to the guide portion 1082 so as to be relativelymovable and relatively non-rotatable with respect to the guide tube 1080by being inserted therethrough. In addition, the guide portion 1082 isformed in accordance with an outer shape of the spindle nut 1060 so asto be capable of locking the spindle nut 1060. Specifically, asillustrated most clearly in FIG. 28, an inner circumferential dimensionD1 of the guide portion 1082 is smaller than an outer circumferentialdimension D2 of the spindle nut 1060 in the present embodiment. Theguide portion 1082 of the guide tube 1080 has a locking surface 1082 bthat opposes the wall 1060 b of the spindle nut 1060 and isperpendicular to the axial direction.

In a state where the door 1002 a of the vehicle 1002 is closed, the coilspring 1022 is in the most compressed state in the door opening andclosing device 1 for vehicles 1001, and the spindle nut 1060 is locatednear the proximal end 1050 b of the spindle 1050 as illustrated in FIG.23. When the electric motor 1031 is driven from this state, the rotationof an output shaft of the electric motor 1031 is reduced by thedecelerator 1032 and transmitted to the spindle 1050, and the spindle1050 is rotationally driven. Since the spindle nut 1060 and the push rod1070 are engaged with the guide tube 1080 and the first housing 1010 soas not to relatively rotate, the rotational movement of the spindle 1050is converted into the linear movement of the spindle nut 1060 withrespect to the guide tube 1080. Specifically, the spindle nut 1060 andthe push rod 1070 move in the axial direction along the inner peripheryof the guide tube 1080. Along with the movement of the push rod 1070,the second housing 1020 moves relative to the first housing 1010. Sincethe first housing 1010 and the second housing 1020 relatively move asdescribed above, the door opening and closing device 1 for vehicles 1001stretches and drives the door 1002 a connected via the shaft end member1021 up to an open position. Here, as illustrated most clearly in FIG.28, the relative movement of the push rod 1070 with respect to the guidetube 1080 is restricted as the wall 1060 b of the spindle nut 1060 andthe locking surface 1082 b formed on the guide portion 1082 of the guidetube 1080 abut on each other.

The spindle nut 1060 is fixed to the push rod 1070 so as not to rotaterelative to the push rod 1070. In addition, since the push rod 1070 isinserted through the guide portion 1082 of the guide tube 1080, therotational movement of the spindle 1050 is converted into the relativemovement of the spindle nut 1060 and the push rod 1070 with respect tothe guide tube 1080. For this reason, the relative rotation of thespindle nut 1060 with respect to the guide tube 1080 can be prevented.

In the cross section orthogonal to the axial direction, the crosssection of the inner peripheral surface 1082 a of the guide portion 1082of the guide tube 1080 is a polygon that is similar to and slightlysmaller than the cross-sectional shape of the outer peripheral surface1070 a of the push rod 1070. For this reason, the relative rotation ofthe push rod 1070 with respect to the guide tube 1080 can be reliablyprevented.

Since the inner peripheral surface of the main body 1081 of the guidetube 1080 opposes the outer peripheral surface 1070 a of the push rod1070 with the interval, the main body 1081 of the guide tube 1080 doesnot come into contact with the outer peripheral surface 1070 a of thepush rod 1070 when the push rod 1070 and the guide tube 1080 relativelymove. For this reason, a sliding resistance when the push rod 1070 andthe guide tube 1080 relatively move can be reduced.

Since the outer circumferential dimension of the spindle nut 1060 islarger than the inner circumferential dimension of the guide portion1082 of the guide tube 1080, the relative movement between the guidetube 1080 and the push rod 1070 can be restricted by locking the spindlenut 1060 in the axial direction by the guide portion 1082 of the guidetube 1080.

A relative rotation restricting portion is constituted by the outerperipheral surface 1070 a of the push rod 1070 whose cross sectionorthogonal to the longitudinal direction forms the polygon and the innerperipheral surface 1082 a of the guide portion 1082 whose cross sectionorthogonal to the longitudinal direction forms the shape correspondingto the outer peripheral surface 1070 a of the push rod 1070.

Since the spindle nut 1060 is molded integrally with the push rod 1070by insert-molding, it is possible to prevent the spindle nut 1060 fromrotating relative to the push rod 1070 and from falling off.

Since the push rod 1070 and the spindle nut 1060 are fixed by theengagement between the through-hole 1071 of the push rod 1070 and theengagement portion 1061 of the spindle nut 1060, the spindle nut 1060can be prevented from falling off from the push rod 1070.

The door opening and closing device 1 for vehicles 1001 of the presentinvention is not limited to the configuration of the above embodiment,and various modifications can be made.

For example, the cross-sectional shape of the spindle nut 1060 is notlimited to the circle, but may be other shapes such as a polygon. Inaddition, the inner peripheral surface of the guide tube 1080 may haveother shapes such as a polygon, and the outer peripheral surface as wellas the inner peripheral surface may have other shapes such as a polygonas long as the wall 1060 b of the spindle nut 1060 and the lockingsurface 1082 b provided on the guide portion 1082 of the guide tube 1080are formed.

In addition, the first housing 1010 is not necessarily divided into theaccommodating portion 1011 and the cover 1012.

The invention claimed is:
 1. A door opening and closing device forvehicles, comprising: a motor drive mechanism; a first housingaccommodating the motor drive mechanism; a spindle drive mechanismconnected to the motor drive mechanism; and a second housing arrangedcoaxially with the first housing and configured to move relative to thefirst housing by the spindle drive mechanism, wherein the spindle drivemechanism includes: a spindle connected to the motor drive mechanism; aspindle nut to be screwed with the spindle; a push rod fixed so as notto rotate relative to the spindle nut; a guide tube through which thepush rod is inserted; and a relative rotation restricting portion thatrestricts relative rotation between the push rod and the guide tube;wherein the relative rotation restricting portion of the spindle drivemechanism comprises: a protrusion on an outer periphery of the push rod;and a guide groove formed in the guide tube and configured to guide theprotrusion of the push rod in an axial direction; and wherein theprotrusion is at a first end of the push rod, and the spindle nut isarranged within the push rod closer to a second end of the push rod thanis the protrusion.
 2. The door opening and closing device for vehiclesaccording to claim 1, wherein the protrusion of the push rod isaccommodated in the guide groove of the guide tube.
 3. The door openingand closing device for vehicles according to claim 1, wherein thespindle nut is insert-molded on the push rod.
 4. The door opening andclosing device for vehicles according to claim 1, wherein the spindlenut includes one of an engagement protrusion and an engagement hole, thepush rod includes the other of the engagement protrusion and theengagement hole, and the engagement protrusion engages with theengagement hole.
 5. The door opening and closing device for vehiclesaccording to claim 1, wherein the guide groove of the guide tubeincludes a locking portion to lock the protrusion in the axialdirection.
 6. A door opening and closing device for vehicles,comprising: a motor drive mechanism; a first housing accommodating themotor drive mechanism; a spindle drive mechanism connected to the motordrive mechanism; and a second housing arranged coaxially with the firsthousing and configured to move relative to the first housing by thespindle drive mechanism, wherein the spindle drive mechanism includes: aspindle connected to the motor drive mechanism; a spindle nut to bescrewed with the spindle; a push rod fixed so as not to rotate relativeto the spindle nut; a guide tube through which the push rod is inserted;and a relative rotation restricting portion that restricts relativerotation between the push rod and the guide tube; wherein the guide tubeof the spindle drive mechanism has a guide portion through which thepush rod is inserted, and wherein the relative rotation restrictingportion of the spindle drive mechanism comprises an outer peripheralsurface of the push rod having a cross section orthogonal to alongitudinal direction forming a polygon and an inner peripheral surfaceof the guide portion having cross section orthogonal to the longitudinaldirection forming a shape corresponding to the outer peripheral surfaceof the push rod.
 7. The door opening and closing device for vehiclesaccording to claim 6, wherein a cross section, orthogonal to alongitudinal direction of the guide tube, of the inner peripheralsurface of the guide portion forms a polygon corresponding in shape tothe polygon formed by the cross section of the outer peripheral surfaceof the push rod orthogonal to the longitudinal direction of the pushrod.
 8. The door opening and closing device for vehicles according toclaim 6, wherein: the guide tube includes a main body having the guideportion on one end side, and the main body has an inner peripheralsurface opposing the outer peripheral surface of the push rod with aninterval.
 9. The door opening and closing device for vehicles accordingto claim 6, wherein an outer circumferential dimension of the spindlenut is larger than an inner circumferential dimension of the guideportion.
 10. The door opening and closing device for vehicles accordingto claim 6, wherein the push rod and the spindle nut are insert-molded.